(Please see the separate page for Lab tests for Homocysteine)

Homocysteine as a Risk Factor for Disease By Laura J. Ninger, ELS 2005Fortunately, those seeking to safeguard their health and longevity can readilymodulate elevated homocysteine levels usingnutritional therapies. These important nutritional strategies may help you avert the wide array of diseases that have been found to accompany excessive levels of homocysteine.Alzheimer’s Disease: Rising levels of homocysteine may predict impending cognitive decline and Alzheimer’s disease.61,62 In one study, high levels of homocysteine were associated with worse cognitive function and elevated homocysteine predicted more severe cognitive decline during seven years of follow-up.61 Moreover, elevated homocysteine was associated with a three times higher risk of Alzheimer’s disease and a 2.6 times higher risk of mild cognitive impairment which typically precedes more severe dementia.62Aneurysm: People who have high homocysteine levels may have an eightfold greater risk of abdominal aortic aneurysm. When an aneurysm ruptures, fatal bleeding can occur unless the patient receives prompt surgical care.63Atherosclerosis: Elevated homocysteine may speed the progression of atherosclerosis. One study showed that atherosclerosis progressed by 35% annually for patients with high homocysteine levels (greater than or equal to 12 μmol/L) but by only 17% per year in people with lower levels (less than 12 μmol/L).64Cardiovascular Disease: About half of all deaths occur because of cardiovascular disease and elevated homocysteine may contribute to 10% of cardiovascular disease cases and deaths.52 Cardiovascular disease risk grows as homocysteine increases and the risk is especially high in people with high blood pressure, diabetes, or high lipid levels.52 Homocysteine damages blood vessels, promotes blood clotting, and generates oxidative stress.52 Some experts estimate that lowering homocysteine could prevent 25% of cardiovascular events,52 and some recommend that all individuals at risk for heart disease should be treated regardless of their baseline homocysteine values.53 Homocysteine poses risks to men, women, and childrenand particularly to people with underlying illnesses.54-56 When researchers followed healthy men for 10 years they noticed that the men with the highest homocysteine levels had nearly twice the risk of cardiovascular disease death.65 Homocysteine was even more dangerous in smokers and in men with high cholesterol.65 In healthy women, increased homocysteine levels were associated with decreased oxygen uptake, indicating poorer cardiovascular fitness.66 Cognitive Impairment: Homocysteine may interfere with healthy mental function.67-69 In one report, healthy elderly people with high homocysteine levels experienced more dramatic cognitive decline over six years than did their counterparts with lower homocysteine levels.68 One study suggested that homocysteine may prematurely age the brain. A rise in homocysteine was equivalent to an extra 4.2 years of age on cognitive performance tests. Homocysteine might thus be a modifiable cause of cognitive decline.69Depression: Depression and high homocysteine appear to be closely related. In people aged 60-64, a higher homocysteine level was associated with a higher prevalence of depression.Bipolar Disorder: Homocysteine may be associated with bipolar (manic depressive) disorder. One study showed that young men with bipolar disorder had much higher homocysteine levels than healthy subjects and homocysteine levels were highest in those with progression of the disease.73 Schizophrenia: Some scientists believe that schizophrenia begins even before birth. Pregnant women with high levels of homocysteine were found to be more likely to have children who later developed schizophrenia. Researchers believe this may be one more reason why pregnant women should take steps to correct elevated homocysteine levels.78Osteoporosis: Elevated homocysteine may adversely affect bone health and fracture risk.74 In healthy adults, high homocysteine was associated with 3.8 times the risk of fracture in men and 2.8 times the risk in women.75 Scientists believe that elevated homocysteine could be a clinical sign of osteoporosis related to nutritional deficiencies.74 High homocysteine may especially increase the risk of fractures in people suffering from underlying illnessessuch as Parkinson’s disease or a history of stroke.76,77Macular Degeneration: Homocysteine may damage eye health and threaten visual function. In fact, scientists found that patients with age-related macular degeneration had significantly higher homocysteine levels than healthy subjects.71,72 Stroke: Over the course of 10 years, men with high homocysteine levels had nearly three times the risk of stroke as men with low levels of homocysteine. High serum folate levels, however, were associated with protection against stroke.79Inflammatory Bowel Disease: High levels of homocysteine in the colon and blood may predispose individuals to two inflammatory bowel diseases: ulcerative colitis and Crohn’s disease. Homocysteine levels were significantly elevated in the colons of patients with inflammatory bowel diseases compared to healthy subjects.48Kidney Disease: Patients with chronic kidney disease were found to have significantly higher levels of homocysteine than healthy people. In fact, 89% of these patients had homocysteine levels greater than 14 μmol/L, which may increase their risk of developing many other diseases.81 ReferencesREFERENCES1. Genest JJ, Jr., McNamara JR, Salem DN, et al. Plasma homocyst(e)ine levels in men with premature coronary artery disease. J Am Coll Cardiol. 1990 Nov;16(5):1114-9.